User blog comment:L1842947/Female Protean Froakie with Toxic Spikes/@comment-31209088-20170209051548

1. The Hidden Ability passage does not apply in Brick Bronze. The reasoning behind this is because the developers want Hidden Abilities to stay scarce and difficult to obtain.

If you were to breed anything with a Hidden Ability, there will be no change whatsoever.

2. I'm not completely certain as I have not actually tried to breed any egg moves.

3. Protean is Greninja's most valued and only usable ability. It causes it's own typing to change depending on the type of the move it used.

TLDR: No, not sure, and amazing. I wouldn't mind trading something for that if you wouldn't mind :)